it is really, really, super easy to do. you don't even need to buy any fancy equipment. the only equipment you need is a pot with a lid and a thermometer. the first thing you want to do is heat up the milk to about 185 to 195 degrees F and then hold it in that range for at least 10 minutes. since i didn't want to warm it up too quickly, i opted for the double boiler method to warm up my milk. since it was the first time i was trying this, i checked the thermometer constantly. once i got the milk in range, i held it there for just over 10 minutes. having it on the double boiler really made it easy to hold it in range - i didn't have to adjust the heat on the stove at all. after the 10 minutes was up, i took the pot of milk off of the double boiler and put it into a water bath, and stirred the milk. this helped to bring down the temperature of the milk fairly quickly - the target temperature being about 115 degrees F. it is hot enough for the yogurt cultures to thrive but not hot enough to kill them. once cooled to the desired temperature, i took about a ladle full of the warm milk into a small bowl, and combined it with a few heaping spoonfuls of the plain yogurt i had bought. i actually used siggi's icelandic skyr, which is a very thick strained yogurt. (in my opinion, i think it's even thicker than greek yogurt!)
once the milk and yogurt are combined to make a smooth mixture, i poured that back into the warm milk, and stirred again, to make sure the cultures were well incorporated into the lukewarm milk. at this point, you're pretty much done. you want the cultures to incubate and do their thing, so i put a lid on the pot, wrapped it up in a towel, and stuck it in the oven overnight. in total it probably incubated for about 6 hours. in order to help keep the milk mixture as warm was possible. i actually had the oven on while i was in the process of warming up the milk, and turned it off once i turned the heat off of the milk.
in the morning, i checked on my little project. i unwrapped the towel, opened the lid and took a look inside. it looked and smelled like yogurt. i then put the whole pot in the fridge. once cooled, i checked the results of my little experiment. before making my own yogurt, i had read that the more fat content in the milk, the creamier and thicker the yogurt would be. so since i had opted to use fat free milk, it was rather thin in consistency, but it was a successful first try nonetheless.
i immediately portioned it out into 3/4 cup portions, about the average for most individual yogurt containers, give or take. i ended up with almost 10 portions from a half gallon of milk! one taste tho, and i knew i was in trouble. i didn't mind the thin consistency, but it was tart. i mean, really tart. i like tart but not that much tart. so for my first bowl of home made yogurt, i tossed in some blackberries and blueberries, a couple drops of vanilla extract, and a sprinkling of sugar. that improved the taste a lot and made me feel like i was eating something healthy. to finish eating this first batch of home made yogurt, i stirred in some macerated fruit (mostly berries) and had a fruit yogurt. as you can also save some as a starter for your next batch of yogurt, i opted to leave one portion as a starter for my next attempt.
after my first try into making yogurt, i found out that one of my co-workers had been doing it for years. she advised that no special equipment was needed, and as long as you keep the pot wrapped in a blanket or towel and out of drafts, you should successfully make yogurt every time. she also let me know that after a couple or rounds of reculturing i'd probably want to start with a fresh starter.
since the first attempt, i've made three more attempts. my second batch of yogurt was strawberry yogurt made from strawberry milk. i used store bought nesquick strawberry milk, a packet of yo'gurmet freeze dried starter, and also a spoonful of my first batch of fresh made yogurt. the strawberry yogurt turned out okay, a little more tart than i had expected, and served with some fresh cut strawberries, it was rather good. just a few days ago, i attempted to make yogurt that was slightly flavored with some vanilla extract, sugar, and honey. as a starter, i used several spoonfuls of my first batch of yogurt. however, this batch did not turn out at all - epic fail! i'm not sure why it didn't turn out, because i can think of more than one factor, but i think the main reason was that perhaps the cultures in my first batch of yogurt were no longer active by this time - it had been over a week after all. so the next day, i attempted it again. this time, the market i shopped at was all out of the horizon fat free organic milk i usually get, so i ended up buying the 1% milk. i made another attempt. i didn't add as much other stuff as i had in my failed attempt. to a half gallon of milk, i added 3 tablespoons of honey, and used the freeze dried culture as my starter. everything else i did the same as before, and again, i had successful batch of yogurt.
however, once i tried the batch made from the 1% milk - i immediately observed several differences from my first attempt. the first was its consistency - for being only 1% milk fat content, it yielded a lot creamier and thicker yogurt than the fat free milk. the second was the smell of the yogurt - i could smell the standard tart smell of yogurt, but it wasn't nearly as pungent as my first attempt. and once i tasted it - there was a difference as well. it wasn't nearly as tart as my first attempt. even though i know the honey that i had added to the milk mixture probably helped, it still wasn't nearly as tart. so now i'm wondering if it was the starter - i tried what was left of the icelandic skyr after making my first batch, and it was really and seriously tart, made worse in my mouth due to the thick texture of it. the 1% milk yogurt was made using the freeze dried starter. i'll have to experiment again to make it with the freeze fried culture (or a first generation reculture) but with no sweeteners added to see how tart the yogurt actually turns out. i'm also planning on trying a different sweetener, such as agave.
